Colloid mill



Patented Jan. 15, 1935 UNITED ISTATES COLLOID MILL Charles P. Tolman,Kew Gardens, N. Y., assignor, l

by mesne assignments, to The Noble &` Wood Machine Co., Hoosick Falls,N. Y., a corporation of New York Application November 8, 1930, SerialNo. 494,252

3 Claims.

The present invention relates to an improvement in colloid mills. Oneobject thereof has been to provide a colloid mill whereby the treated orcompleted product can be separated automatically and continuously fromthe uncompleted or partly treated product and whereby said partlytreated product may be returned to the mill or retained therein forfurther treatment or until it reaches the completed state or condition.

In present colloid mill practice, itis not unusual for a product whichappears to be in effective and permanent dispersion to show extensivesedimentation after standing for a time. Furthermore, where, in thecourse of treatment in a colloid mill, undispersed or unreducedparticles are enveloped in a mass of dispersed or reduced particles, theshearing' forces are somewhat cushioned or nullied thus diminishing theshearing or dispersing` effect upon the unreduced or undispersedparticles. According to my invention, I preferably separate theunreduced particles from thosev which are of celloidal fineness as soonas may be after the latter are formed so that the full shearing force ofthe mill may be directly employed upon the unreduced particles.

My invention is illustrated in the embodiments thereof described in thepresent specification and shown in the accompanying drawing, inwhichFigure 1 is a central longitudinal section of one form;

Figure 2,`a central longitudinal section of a modified form; and fFigure 3, a diagrammatic representation of a plurality ofconnectedcolloid mills arranged in such a way that the finished productis continuously removed while the unnished product is segregated andadvanced to another mill or other mills for further treatment or untilit reaches the nished state.

`Referring to the drawing, a colloid mill according to my inventionincludes the usual or special cooperating surfaces arranged to effecthydraulic shear and means for separating relatively reduced or dispersedparticles of product from portions thereof which are unreduced orundispersed and continuing the treatment of said unreduced portionswhile the reduced or dispersed portions are permitted to be removed. Asindicated in Figure 1, one form of apparatusfor this purpose includes acasing or stator l having a valve controlled inlet 2, the interiorsurface of said casing being of truncated conical contour and providedwith annular grooves 3, 4, 5 and 6. A rotor 7 mounted on shaft 8 isadjustable relatively to the interior surface off'stator 1 by anysuitable adjusting means 9. 10 communicates with groove 3 and iscontrolled by means of a valve 11. A discharge pipe 12 communicates withgroove 4 and is connected by means of a pipe 13 with a discharge pipe 14com- A discharge pipe municating wthgroove 5. A valve 15 controls thedischarge pipe 12 and a valve 16 is placed in the connecting pipe 13.The groove 6 is discharged through a pipe 17 provided with a controlvalve 18.

It will be noted in connection with Figure 1 that the rotor 7'is ineffect a hollow truncated cone having the outer edge of its open endbeveled at 19. Another member, here shown as a second rotor 20 mountedony shaft 21 cooperates with the interior surface of rotor 7 and isyadjustable with respect thereto `by means of any suitable adjustingdevice, as 22. The outer end of rotor 20 is beveled'at 23 to form anannular channel between said rotor and the edge of the open end of rotor7. Shaft 21 also carries a plurality of paddles or blades 24 positionedand adapted to produce a. centrifuging effect in the space between theouter end of rotor 20 and the adjacent end of casing l. The rotor 7 isprovided with a plurality of outlet ports 25 communicating with thevgroove 5.

In operation, relative movement between rotor 7 and the casing or statorl is effected simultaneously with relative movement between rotor 7 androtor 20, said rotors being rotated either in opposite directions or inthe'same direction at different speeds, or as desired. In some cases, itmay be advantageous to arrest rotation yof rotor 20 and actuate only therotor 7. However, to produce a centrifuging effect, rotor 20 is actuatedand causes the heavier or larger particles of the material fed into theinlet chamber through the pipe 2 to be moved outwardly into the groove3. The lighter or smaller particles are caught in the annular channelbetween the bevel 23 and the adjacent inner edge of rotor '1. 'Iheapparatus will preferably be set to separate the particles of materialon the basis of their readiness for quick dispersion or modificationinto colloidal condition. The particles not properly or completelyprepared may be discharged through pipe l0 for further preliminarytreatment if desired. The remaining finer orI lighter material issubjected to shearing action between the inner surface of rotor 7 andthe outer surface of rotor 20 and is dis- Icharged through ports 25,groove 5 and pipe 14 if desired. Such of the heavier material as movesdown between stator l' and rotor 20 will be accumulated 4in groove 4 andmay be discharged therefrom through pipe 12. The remainder will continuedownwardly and out through the groove 5 and discharge pipe 14, or it maydischarge through groove 6 and outlet 17.

When valve l1 is opened, thus permitting the heavier particles to bewithdrawn from the apparatus, the device works as a centrifugeseparator, retaining only the finer or lighter particles. When valve 11is closed the beaver particles are forced downwardly between casing 1and the rotor 'I and' subjected to normal shearing action and may bewithdrawn as above described. By closing valve 15 and valve 16 they maybe subjected to further shearing action until they reach the groove orthe groove 6 as desired. In this way, the device operates as a combinedcentrifuge separator and colloid mill with the dispersing and separatingaction taking place simultaneously and in a continuous operation.

Referring now to Figure 2, a hollow truncated conical rotor 30 ismounted on shaft 31 to rotate within a casing or stator 32, the interiorsurface thereof being provided with annular grooves or recesses 33, 34,35 and 36. An outlet pipe 37 controlled by a valve 38 communicates withthe recess 33. An outlet pipe 39 controlled by a valve 40 communicateswith recess 34. An outlet pipe 41 controlled by valve 42 communicateswith recess 35. An outlet pipe 43 controlled by a valve 44 communicateswith recess 36. The rotor 30 is provided with a plurality of ports 45communicating with recess 35.

Another rotor 46 mounted on a shaft 47 has a portion of its exteriortruncated conical surface arranged in lm shearing relation to a portionof the interior conical surface of the casing or stator 32. Anotherportion of the truncated conical surface of rotor 46 is in lm shearingrelation to a portion of the interior truncated conical surface of rotor30 which is open at one end to receive said portion of the rotor 46. Ina preferred form of apparatus, the open end edge of rotor 30 presents abeveled surface 60 outwardly towards groove 33 and also aV beveledsurface 61 inwardly towards rotor 46 which is itself tapered at 62opposite said interiorly disposed bevel to form an annular channelbetween the upper edge of the rotor 30 and the tapered portion of rotor46.

Material is supplied to the apparatus for treatment through an inletpipe 48 controlled by a valve 49 and communicating with an annularrecess or groove 50. The rotor 46 is provided intermediate its ends withan annular groove 51 within which are disposed a plurality of radiallyarranged paddles or blades 52 with their outer edges exposed toward thegroove 33 in casing 32.

In operation, material to be treated is fed into groove 50 through pipe48 and is given a combined longitudinal and rotational movement betweenrotor 46 'and the interior surface of casing 32. Upon reaching theposition of paddles 52 in groove 51, the heavier particles are thrownoutwardly toward groove 33 while the lighter particles work downwardlybetween the outer surface of rotor' 46 and theinner 'surface of rotor30. Further reducing treatment may be accorded to the heavier particlesif valve 38 in pipe 37 is closed. Otherwise, the heavier particles maybe withdrawn or discharged from the apparatus. The lighter particles' ineithercase are further subjected to shearing action as above described.1f valve 38 is closed,l the heavier particles are subjected to shearingaction between the inner surface of casing 32 and the outer surface ofrotor 30 and may be discharged at groove 34 through pipe 39 if desired.If this pipe is closed by means of valves 40 and 42, the material may beagain subjected to further shearing action in that portion of theapparatus between grooves 34 and 35, and discharged from the latterthrough pipe 41. If pipe 41 is closed by valve 40, the discharge fromgroove 35 will proceed through to groove 36 to be discharged throughpipe 43.

in Figure 1 wherein an initial separating actionV takes place as soon asthe material comes in contact with the blades or paddles 24.

In the arrangement shown in Figure. 3, material to be treated is fedinto a combined centrifuge and colloid mill, having centrifuging means,such for example asthose hereinabove described, if desired. 'I'hefinished product is withdrawn from the rst mill 5,1 through pipe 52while the unfinished product discharges from said first mill.

through pipe 53 into a second mill 54. 'I'he finished product from 54discharges through 55 while the unfinished product discharges through 56into a third mill 5'?, all of said products finally reaching a suitablecontainer or collecting tank, as 58. It is contemplated that thepartially treated or finished material may be re-treated in the same ordifferent mills as often as desired or necessary to produce the finishedproduct, while such product as is properly finished is continuouslywithdrawn from each mill as it is formed. With this arrangement and modeof operation, the time and energy of treatment is not wasted uponproducts which have been finished or completed in a relatively shorttime, thus aiIording a measure of economy which is not possible withmills of known types in the prior art which present only a single pathover which the entire product must be moved regardless of the fact thatlarge portions thereof are completed after relatively short periods oftreatment.

I claim as my invention:

1. In a colloid mill, the combination of ,a stator member having aninteriorly exposed recess and an outlet conduit communicating with saidrecess, a rotor member in spaced nlm shearing relation to interiorportions of said stator and overlapping a portion of said exposedrecess, a third member having portions in spaced film shearing relation`to said rotor member, and means for moving parts of the material beingtreated into said exposed recess and other parts of said material intoposition for shearing action between said rotor and said third member.

2. In a colloid mill, the combination of a hollow stator having an inletopening, a rotor having a portion of its surface in film shearingrelation to an interior surface of said stator, centrifuging meansmounted on said rotor, and a second rotor having a nlm shearing surfacein operative relation to an interior surface of 'said rst mentionedrotor and positioned to exert ef- -fective film shear in respect toaportion of the material acted upon by said centrifuging means. 3. In acolloid mill the combination of three concentrically-arranged film shearproducing members including a stator and two rotors, one of said rotorshaving a portion interposed in film-shearing relation between saidstator and said other rotor to form therewith respectively an outer andan inner shearing gap, and said other rotor being provided withcentrifuging means operatively arranged in relation to the inlet ends ofsaid shearing gaps whereby heavier particles of the material treatedenter said outer gap and lighter particles enter said inner gap. CHARIESP. TOLMAN.

